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Publication numberUS20090243394 A1
Publication typeApplication
Application numberUS 12/058,624
Publication dateOct 1, 2009
Filing dateMar 28, 2008
Priority dateMar 28, 2008
Also published asUS8629576
Publication number058624, 12058624, US 2009/0243394 A1, US 2009/243394 A1, US 20090243394 A1, US 20090243394A1, US 2009243394 A1, US 2009243394A1, US-A1-20090243394, US-A1-2009243394, US2009/0243394A1, US2009/243394A1, US20090243394 A1, US20090243394A1, US2009243394 A1, US2009243394A1
InventorsRichard C. Levine
Original AssigneeNigelpower, Llc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Tuning and Gain Control in Electro-Magnetic power systems
US 20090243394 A1
Abstract
Tuning and gain control as described for magnetic power systems, including different ways to change the characteristic of transmission and reception.
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Claims(32)
1. A magnetic power coupling system, comprising:
a receiver, that receives a magnetic signal that conveys power therein, and converts said magnetic signal into power, and produces a power output, said receiver including a connection to a load, wherein said connection allows coupling said power to said load, wherein said receiver creates an automatic feedback signal, said automatic feedback signal representing at least one characteristic of the power coupling, and said automatic feedback signal including at least information indicative of a concentration of the magnetic field received by the magnetic signal, and said automatic feedback signal being indicative of a characteristic of the power coupling that changes based on environmental conditions.
2. A system as in claim 1, further comprising a transmitter that changes a characteristic of the power coupling based on said automatic feedback signal.
3. A system as in claim 2, wherein said feedback control changes a directionality of the electromagnetic field in said transmitter.
4. A system as in claim 1, wherein said feedback signal controls changing a characteristic of the power coupling.
5. A system as in claim 4, wherein said changing the way the signal transmits comprises changing a position of an antenna.
6. A system as in claim 4, wherein said changing the way that the signal transmits comprises controlling a direction of the magnetic field created by the antenna without physically moving or reorienting the antenna.
7. A system as in claim 2, wherein said automatic feedback signal is sent from said receiver to said transmitter via a short range communication technology.
8. A system as in claim 2, wherein said automatic feedback signal is sent from said receiver to said transmitter via a cell phone communication channel.
9. A system as in claim 7, wherein said short range technology is an infrared channel.
10. A system as in claim 1, wherein said receiver changes its resonant frequency responsive to said automatic feedback signal.
11. A system as in claim 1, wherein said receiver changes its magnetic frequency responsive to said automatic feedback signal.
12. A system, comprising:
a magnetic power coupling system, comprising a magnetic transmitter, that receives electric power from a power source to be transmitted to a remote receiver, and couples said power to said remote receiver magnetically by creating a magnetic field, said magnetic power coupling system also including a receiving part that receives a signal indicative of a further signal indicative of a feedback control, and changes a characteristic of the created magnetic field based on said signal indicative of said feedback control.
13. A system as in claim 12, wherein said transmitter changes a way that the signal is transmitted [responsive to said signal indicative of said feedback control.
14. A system as in claim 13, wherein said changing the way the signal transmits comprises changing a position of the antenna.
15. A system as in claim 13, wherein said changing the way that the signal transmits is generated comprises controlling a direction of the magnetic field created by the antenna without moving or reorienting the antenna.
16. A system as in claim 15, wherein said signal indicative of a feedback control from a receiver is received via a short range channel technology.
17. A system as in claim 15, wherein said signal indicative of a feedback control from a receiver is received via a cell phone communication channel.
18. A system as in claim 16, wherein said short range technology is an infrared channel.
19. A system as in claim 16, wherein said transmitter changes a resonant frequency of said transmitter based on said signal indicative of said feedback control.
20. A system as in claim 15, wherein said transmitter changes a driving signal that sets a magnetic frequency.
21. A system as in claim 20, wherein said changing uses a digital bitstream to create a sine wave based on said digital bitstream.
22. A system as in claim 21, wherein said sine wave has a adjustable frequency that changes depending on a specific bitstream which is used.
23. A system as in claim 22, further comprising a heterodyne signal that adds a constant frequency to a frequency of the generated sine wave.
24. A system as in claim 22, wherein said changing the way the signal is generated, changes a frequency of the generation.
25. A system as in claim 22, wherein said changing the way the signal is generated, changes a component of the polarization.
26. A system as in claim 25, wherein said polarization causes the field to impinge on the antenna at a specified direction.
27. A method, comprising:
creating a magnetic power field to be coupled to a load;
detecting if the load is present, and if so allowing a magnetic coupling field to be coupled to the load produce power to a load; and
determining when the load is not present, and automatically shutting off transmission when the load is not present.
28. A method, comprising:
receiving electric power from a power source, to be transmitted to a remote receiver,
coupling said power to said remote receiver magnetically by creating a magnetic field;
receiving a signal indicative of a signal indicative of a feedback control, and
changing a characteristic of the created magnetic field based on said signal responsive to ????] said feedback control.
29. A method as in claim 28, wherein said changing the way the signal transmits comprises changing a position of the antenna.
30. A method as in claim 28, wherein said changing the way that the signal transmits is generated comprises controlling a direction of the magnetic field created by the antenna without moving or reorienting the antenna.
31. A method, comprising:
using electric power to create a magnetic field that has the capability to convey power from a first location, where the electric power is created, to a second place remote from said first place;
receiving the magnetic field in a receiver that is remote from a source of said electric power and is not connected thereto by an electric wire, and, based on said receiving, producing an electrical output signal based on said magnetic field;
receiving a signal indicative of a feedback control in said receiver; and
based on said feedback control signal, changing a characteristic of the created magnetic field based on said signal responsive to said feedback control.
32. A method as in claim 31, further comprising changing a way that the signal is transmitted based on said signal responsive to said feedback control.
Description
  • [0001]
    Our previous applications and provisional applications, including, but not limited to, U.S. patent application Ser. No. 12/018,069, filed Jan. 22, 2008, entitled “Wireless Apparatus and Methods”, the disclosure of which is herewith incorporated by reference, describe wireless transfer of power.
  • BACKGROUND
  • [0002]
    The transmit and receiving antennas described here are operated at frequencies exactly equal to or close to their resonance. The receive antenna is preferably of a small size to allow it to fit into a mobile, handheld device where the available space for the antenna may be limited. An embodiment describes a high efficiency antenna for the specific characteristics and environment for the power being transmitted and received.
  • [0003]
    One embodiment may be usable in a configuration that transfers power between two antennas by means of the intermediate process step of storing all or part of the energy in the near field of the transmitting antenna, rather than sending the energy into free space in the form of a travelling electromagnetic wave.
  • [0004]
    Embodiments operate with high quality factor (Q) antennas.
  • [0005]
    In one embodiment, two high-Q antennas are placed such that they receive power similarly to a loosely coupled transformer, with one antenna inducing power into the other. The antennas preferably have Qs that are greater than 1000.
  • SUMMARY
  • [0006]
    The present application describes a number of improvements for an electromagnetic power transfer system, with emphasis on embodiments that deliver the majority of the power via the magnetic field. Embodiments which deliver the power substantially via the electric field, or via both the electric and magnetic field(s), are included in the scope of this disclosure.
  • An Aspect Describes Adaptive Beam Steering
  • [0000]
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • [0007]
    FIG. 1 shows a block diagram of the overall system.
  • DETAILED DESCRIPTION
  • [0008]
    A basic block diagram of an embodiment is shown in FIG. 1. A transmitter 100 is located spaced from a receiver 150 across a spacing 101. The spacing typically comprises an area or volume of air, a wall, or any other separating medium. Importantly, the connection between the transmitter and receiver is wireless—in the sense that the power delivery is effected without an electrically conductive wire between the transmitter and receiver. The receiver receives power via a wireless transmission. That received power is coupled to a load.
  • [0009]
    In an exemplary embodiment, the transmitter 100 comprises an electric plug 102 that plugs into an electric outlet, a power source. The electric outlet typically furnishes alternating current (ac) having a sinusoidal voltage waveform with a frequency of either 50 or 60 Hz and a root-mean-square (RMS) voltage of nominally either 220 or 120 volts, respectively. The transmitter is typically constructed of at least two modules whose technology is well known to those of ordinary skill in the art: A so-called “power supply” (more precisely a power waveform converter) which produces an internal intermediate power waveform (typically uniform direct current—dc), and an oscillator having adjustable amplitude, frequency and phase for a sinusoidal waveform. In addition to these two modules, a control unit 105 controls characteristics of the transmitting, including changing the frequency of the electric signal, turning it on and off, and carrying out various features as described in these embodiments. The signal is coupled to a coupling loop 110, which induces transmitted power into a resonant antenna 115. Antenna 115 may optionally further utilize a connection of an inductor and/or capacitor forming a resonant LC circuit. This produces a magnetic field across an area, the magnetic field shown generally at 125.
  • [0010]
    An exemplary magnetic field receiver circuit is also shown and is formed of a receiving antenna which couples to a receiver controlling circuit 160. Receiver controlling circuit 160 may carry out various aspects of control as described herein by receiving the magnetic field signal, sensing various parameters of the received signal, and rectifying an output signal to produce a power output 165 to a load 170.
  • [0011]
    The overall efficiency of this kind of system may be measured as the ratio of the power delivered to the power transmitted. An embodiment describes increasing the efficiency of this system via the optional use of a feedback control in an embodiment. The feedback control determines characteristics of the power coupling, and optimizes parameters to improve the power coupling.
  • [0012]
    The automatic feedback control may optimize the directionality and hence the concentration of the electromagnetic field onto the space in and immediately around the receiver 150.
  • [0013]
    For example, FIG. 1 shows how the magnetic field 125 may be concentrated in the immediate neighborhood and interior of the receive antenna or coil 125. Any magnetic field that is outside this immediate space 156 is in essence wasted. This is overspray power that goes in other directions. Directing the power to the spatial region 156 minimizes the amount of the wasted power. This in turn increases the percentage of the power that is received and used by the receiver, and hence this can improve the efficiency of this system.
  • [0014]
    An exemplary embodiment discloses “sniffing” the power location and/or distribution, to determine parameter values leading to optimum power delivery, and to optimize the spatial pattern of the power delivery.
  • [0015]
    A first optimization may optimize the transmission according to an output variable. The output variable may be dependent on the optimal setting of scalar or vector parameters such as signal phase or beam direction, respectively.
  • [0016]
    A first embodiment may include a directional control of the azimuth angle and elevation angle of the transmit antenna. For example, the antenna 115 may have a directional control shown generally as 116. The directional control 116 may be a mechanical movement device, or may use phased array type techniques. Operation of the directional control steers the direction 117 of the maximum output magnetic field of the antenna—sometimes called the “main lobe” of field intensity.
  • [0017]
    The direction device may be a pan and tilt gimbal having vertical and horizontal axes allowing adjustment of the azimuth and elevation angles. A first device may control movement around the vertical axis, and a second device may control movement relative to the horizontal axis. The rotations can be manually controlled, or can be carried out based on an automatic or semi-automatic movement utilizing electrical, hydraulic, pneumatic or other movement devices, in which case the devices may be, for example, electrically-controlled motors or actuators.
  • [0018]
    The controller 160 also produces an output signal 161 that is used for feedback. Different techniques of feeding back the information can be used as described herein.
  • [0019]
    According to a first embodiment, the transmitting antenna 115 may be scanned across various ranges of parameters either during the power transmission or prior to transmission. When powered device 170 itself includes a battery 171, power from that battery can be used during this time of scanning. It is preferable that this battery be a rechargeable battery (e.g. a secondary battery). The scanning can therefore cause temporary interruptions in power to the powered device 170, but the device may continue to operate from the power in the battery 171. The scanning may improve the power coupling, and may thereafter permit improved power coupling. Therefore, the power can be interrupted at intervals to allow periodic readjustment of the characteristics.
  • [0020]
    Device 170 may have a capacitor or other energy storage means, instead of or acting in conjunction with the battery 171. Other devices capable of temporarily storing energy, such as a low-loss inductor or an electromechanical flywheel may be used to replace or supplement the battery 171.
  • [0021]
    In one embodiment, a human operator can manually scan over a range of angles to “sniff” out the optimal parameter setting for maximizing delivered power. A visual display, sound generator, or vibration device may be used to indicate to the person making adjustments the delivered power for different adjustment parameter values. This may be done, for example, when the system is used in a fixed installation, such as a room. Users can adjust the azimuth and elevation of the transmit antenna to maximize the received power transfer, much in the same way that rabbit ears were used for antenna adjustments on television sets several decades ago.
  • [0022]
    Another embodiment may use electric motors or actuators that are controlled by the controllers. The directional device 116 in this embodiment uses electrical motors or actuators. In this embodiment, the device may first scan along a path defined by a lookup table that has a list of the most likely angles to be optimal. For example, this embodiment may carry out scanning over values that have been previously found to be local maximums or global maximums. Optimization techniques such as linear programming and simplex may be used to determine these local or globally optimum values.
  • [0023]
    According to another embodiment, the antenna 115 uses phased array techniques. The antenna uses a controlled phase or time delay of a driving waveform to control a phase or time delay of one power-carrying waveform relative to the waveforms of other antennas in the array. This allows changing the directionality and beam width of the magnetic field 125 using electrical adjustments of the amplitude and phase from each antenna. For example, this may also use the magnetic shielding and/or steering techniques to electronically adjust the beam width output. In this technique the beam width and direction can be adjusted to direct a maximum amount of magnetic field to the receiving antenna and to avoid or minimize transmitting magnetic field in undesired directions.
  • [0024]
    In this embodiment, for example, the feedback signal 165, or a signal derived therefrom, may be communicated back to the transmitter. Different techniques for doing this are discussed herein.
  • [0025]
    One embodiment may completely shut off or greatly attenuate transmitter power when the feedback signal 161 is not received back, or when analysis indicates via well-known methods of detecting a signal in the presence of “noise” that there is no accurate feedback information. For example, this may stop the power from being transmitted when there is no receiver in place or when the receiver is receiving less than a specified amount of power.
  • [0026]
    This conveyance of the feedback signal uses a signal or information channel from the receiver 150 back to the transmitter. A number of different techniques may be used to send the feedback information back to the control signal.
  • [0027]
    According to a first embodiment, the feedback conveyor 162 may itself be connected to the powered device 170. For example, when the powered device is a device whose functional purpose includes transmission of a signal, a logical channel within that powered device can be used to send the information stream. For example when a cell phone is being powered, a logical communication channel within the cell phone can send the information stream. Cell phone handsets, for example, often use a message format that transmits such information from the handset to the mobile base station to identify the handset. Among other uses this allows registering a new handset or “attaching” it to the cellular network.
  • [0028]
    A new information element can be added to the other information elements as part of the wireless powering system design. For example, when the powered device is integral with the receiver 150, the connection 163 may connect to a special logical or physical channel within the powered device to allow transmission back to the power transmitter. In this embodiment, a report indicative of amount (or other characteristics) of received power (for example, estimated signal to noise ratio) can be sent back to the controller 105 using minor modifications of existing cellular messaging techniques. For example, a new message type can be defined and used, via software changes, in the fast associated channel (FACCH) or the slow associated channel (SACCH) of GSM cellular.
  • [0029]
    Another embodiment may send a feedback signal from the feedback unit 163 directly to a receiver 119 within the transmission device. In the embodiment, the power transmission may only be feasible over a limited length of distances such as 3 to 6 meters (10 to 20 feet). Various existing or future low-power techniques such as Bluetooth can also be used to wirelessly transmit over this short distance.
  • [0030]
    Another embodiment may transmit over a non-RF channel, such as using an acoustic, infrared, or ultrasonic signal. The hardware could use acoustic transducers—microphone; IR diode source and receiver, etc. Infrared and ultraviolet techniques may also be used since this is over short distances.
  • [0031]
    Another embodiment disclosed herein uses the controller 105 to match to the resonant frequencies of the transmit and receive antennas. Efficiency can be maximized by accurately adjusting parameters such as physical dimensions and use of dielectric or magnetic materials. It is important to maintain precise matching in order to keep the Q of the antenna at a very high level. In a preferred embodiment, the Q of the antenna is designed to be and is to be maintained, for example, over 1000 and preferably even higher. However, the inventors found that even when the components are manufactured to precise dimensions, dielectric or magnetic objects in the near field of the antenna(s) can change the resonant frequency and/or change the Q of the coil. In an embodiment, dynamic adjustment of these values is carried out. The dynamic adjustment may cause increases or decreases in the sensitivity of controllers or the number and type of control devices for the system.
  • [0032]
    In an embodiment, the waveform delivered from the control unit 105 to the antenna 110/115 may be adjusted. The control unit 105 may interact with an oscillator 106 which may be electrically adjustable with regard to several parameters: frequency and/or amplitude and/or phase. This may use for example a variable inductor or variable capacitor such as a varactor, or a combination of fixed and variable components. The adjustment can be controlled by trial and error, for example, to maximize the delivered power amount. As stated, the feedback control may also be automatic and continual.
  • [0033]
    The oscillator 106 can also be a digital oscillator that creates a digital bit-stream based on a table stored in memory. The digital bit-stream represents a sampled version of a sine wave. In this embodiment, the oscillator may include a digital to analog converter that produces an output representative of an analog sine wave. Reading different information from the table changes the frequency or phase of the transmission accordingly.
  • [0034]
    This may be combined with a heterodyne style up converters such that the variable frequency sine wave is generated at a relatively low nominal frequency. For example, the sine wave may be generated at 100 kHz, and then “mixed” with a constant frequency sine wave of 1300 kHz, for example. This, together with a well known use of a filter or cancellation mechanism to suppress the undesired “image frequency” at 1200 kHz, could create a waveform at nominally 1400 kHz as the output of the up converter. This 1400 kHz waveform will imitate any change in amplitude, frequency or phase that occur in the 100 kHz waveform. This 1400 kHz wave can be further amplified and used to produce the magnetic field transmission.
  • [0035]
    The above part of this disclosure describes modulating the amplitude and/or frequency and/or phase of the power transmitter signal. Adjustments in these same parameters at the power receiver can be done by modifying the parameters of the components such as the inductance of coils, or the capacitance of capacitors via changes in their mechanical shape or spacing.
  • [0036]
    Varactors are well-known semiconductor dielectric devices that can be used to change their small-signal capacitance by purely electrical means. The values of so called “parasitic” or intentional parameters can be modified by introducing or moving dielectric or magnetic objects in the vicinity of the antenna.
  • [0037]
    Individual adjustment of the resonant frequency of each receiver is a preferred embodiment when using multiple receive devices that accept power from a single transmitter. It is also possible alternatively to use one transmit antenna for feeding several transmit power waveforms, each having distinct frequency and phase, with all of them being produced by the same or multiple frequency transmitter(s), as an alternative to use of multiple separate discrete transmitters.
  • [0038]
    In the embodiment, the feedback 162 may be used to provide information from which a frequency can be adjusted. The transmit frequency in an embodiment can be continually adjusted.
  • [0039]
    Another embodiment may control and match phase in addition to matching the frequency. The phase adjustment may become even more important when there are multiple signal sources, each arriving at the receiver. The phase adjustment may be carried out by adjusting the phase or time delay of the sine waves. For example, a sine wave and cosine wave of the same frequency can be created and added together with each wave amplitude adjustable value components such as adjustable resistors, inductors or capacitors may also be used to create a phase shifted sine wave. This system may also, however, change the amplitude of the resultant wave, and as such may be compensated by use of an adjustable amplifier.
  • [0040]
    Polarization matching can also be used to optimize efficiency. In a preferred embodiment primarily using magnetic fields, such fields are customarily described by a vector (symbol B or H), to indicate the intensity and direction of that field. Another embodiment may in contrast primarily use an electric field, where the vector E represents the intensity and direction of the field. For the structures considered in this document, the two vectors B and H will always be locally parallel to each other and may be thought of as two representations of the same magnetic field expressed in different units, namely amp/meter for H and volt.second/meter2, or Teslas, for B.
  • [0041]
    Linear polarization can be matched in a first [???] embodiment. The optimal polarization in a magnetic power transfer system is to orient the B (or H) field in and around the receiver antenna coils, so the B field is perpendicular to the geometric plane of the receive coils. In the case of a design in which not all coil turns lie in the same or parallel planes, an “average” or “effective” or “composite” single plane can be determined via well-known methods of calculation or measurement. In contrast, in a power transfer system primarily using the electric or electromagnetic fields, the receive antenna has a composite or equivalent vector polarization, and the maximum power will be transferred when the local electric field vector E of the power transmission wave is parallel to that receive antenna polarization vector. For a multiple element antena there is likewise a “composite” overall polarization vector, and maximum power transfer occurs when the vector E field is parallel to it.
  • [0042]
    In another embodiment, there are multiple transmitting antennas, and hence waves may arrive from multiple transmitting antennas or from different parts of a transmitting antenna array. These waves may have the same frequency but arrive with different E, B (and H) field directionalities. When different parts have different directionalities, the combination of these waves may form a circular or elliptically polarized wave.
  • [0043]
    The elliptically polarized wave is considered as a more general case, and is hence considered herein. The instantaneous E and B fields' polarization of such a wave appears to rotate in space. The tip of the E field vector, if it were visible to an observer, appears to trace out an ellipse during each cycle of the rf oscillation. The B field also appears to trace out an ellipse of its own in space. For such an elliptically polarized wave, maximum magnetic field power delivery occurs when the major axis of the B field ellipse is perpendicular to the effective plane of the receiving antenna coil, or for the electric field case, when the major axis of the E field ellipse is parallel to the polarization vector of the receive antenna.
  • [0044]
    Hence, for both these cases optimal power delivery occurs when an axis of the ellipse is perpendicular to the plane of the coil
  • [0045]
    The E and B fields can be oriented using two or more transmit antenna coils, each of which is oriented such that the center line axes of these coils are mutually perpendicular. Using 2 coils allows the direction of the E field to be adjusted to any desired orientation within a plane. A different number of coils can also be used. For example, three coils can be used to adjust to any desired orientation in three-dimensional space. Any desired electromagnetic wave of any desired spatial orientation can be produced by three mutually perpendicular transmit coils, each driven with a sinusoidal current of the same frequency.
  • [0046]
    For those embodiments where the optimal location or direction of the main lobe of the radiated power and the optimal polarization of the wave may change with time, the feedback control system is designed to achieve the results described in the previous paragraphs. These changes may be due to, for example, movement of the device that receives the power and its associated antenna coil. Linear programming or other well known methods of optimization can be used in the design of the feedback control system to carry this out.
  • [0047]
    Another embodiment may transmit power over radio frequencies. A substantially un-modulated sine carrier frequency waveform may be used along with other waves that include carrier frequencies used for communication. For example, in one embodiment, a carrier frequency different and distinct from the power transmission frequency may be used to send information such as feedback information.
  • [0048]
    The power and signaling frequencies can be any value; however use of lower radio frequencies has several advantages, including these:
  • [0049]
    Larger transmit power (and thus larger Receiver power delivered) are permissible at lower frequencies under FCC, CRTC-DOC and EU limits on rf exposure, without the risk of harm to people in the vicinity.
  • [0050]
    The electrical “skin depth” of surface electric currents on conductors, such as the antenna coil, is greater at low frequency, so that the effective electric resistance of these conductors is lower and the Q and efficiency are greater.
  • [0051]
    The near field region around an antenna is larger at low frequencies, thus providing a possibility of greater power delivery distance with high power delivery.
  • [0052]
    Techniques are used to avoid or minimize interference with communication receivers nominally using the same frequency.
  • [0053]
    In contrast to a modulated radio waveform having a non-zero bandwidth, the single frequency, nominally zero-bandwidth, power transmission sine wave can be advantageously used, via the methods described here, on frequencies that also carry communication signals, without significant degradation of said communication signals. Several types of widely used modulation on the communication channel are suitable for this purpose. Slightly different methods are used for two categories of interference minimization. At the time of filing, these methods are not specifically approved by government regulatory agencies, who currently prohibit any type of radio signal except as licensed, in most radio bands. Changes in the relevant regulations might be necessary for legal operation on licensed radio communication bands using the methods described here.
  • [0054]
    This system may also limit the size region of possible Interference. The substantially un-modulated rf power carrier sine wave used in these embodiments is transmitted in a directional beam and is intended to be severely attenuated in the transmission beam, at greater distances than a few meters. Therefore, the possibility of interference with a communication receiver is significant only in a relatively small region of space near the power receiver and power transmitter antennas, and not over the entire area of a city as for broadcast interference.
  • [0055]
    Other techniques can be used to minimize or avoid interference with modulated signals occupying the same part of the radio spectrum. One method involves setting the power RF frequency almost or precisely equal to the communication carrier frequency (for some types of modulation, this is the zero-deviation frequency of the communication carrier). This placement of a second carrier frequency is seldom if ever used in prior art radio system design, because of the widely held belief that intentionally transmitting any waveform within the frequency spectrum already occupied by a modulated communication signal will always cause degradation of the communication signal. In an alternative method, the power carrier frequency is intentionally set sufficiently far above or below the communications carrier frequency so as to be substantially outside of the nominal communication signal bandwidth, and therefore “filtered out” by the communication signal receiver. This latter method might be used only after a prior test of the first method and also if it outperforms the first method.
  • [0056]
    The method for a particular installation is selected based on the type of modulation used on the communication carrier in the vicinity and the power level of the communication signal at the communication receiver antenna, and the results of modified SINAD tests. SINAD is an abbreviation of signal, interference, noise and distortion. The modified SINAD test procedure is described later. Thus the power settings and adjustments may be different in different specific installations. These settings and adjustments may be accomplished by manual means at installation or repair time, or they may be automatically controlled by an automatic feedback control loop including a monitoring communications receiver to measure the amount of interference. The monitoring communications receiver may be the very same communications receiver used by the rf power carrier user(s), or it may be a distinct receiver.
  • [0057]
    Different categories of modulation can be separated regarding their performance in the presence of noise or interference. Some types of modulation are characterized by means of a parameter called its “capture ratio.” Modulation methods in this category typically do not have a carrier or other fixed frequency component when an input signal is varying. Examples in this category include FM (frequency modulation), PM (phase modulation) and QAM (combined phase and amplitude modulation—called quadrature amplitude modulation).
  • [0058]
    The capture ratio is a special value of the SNR, the ratio of signal power (including noise) to the sum of noise and interference power (SNR=(s+n)/(n+i)) which is the boundary value for SNR, separating a range that allows almost perfect reception for all SNR values above this boundary value, in contrast to degraded reception quality for all SNR values below this, but it applies only to certain types of modulation.
  • [0059]
    An objective of a radio communication system designer using a capture-ratio type of modulation is, in view of expected noise and interference, to place and assign parameter values such as Transmitter power, antenna gain, path loss, etc., to each communication link so that the SNR is above the capture ratio. An object of this invention is to keep the total rf noise and interference at the power Receiver antenna low enough so that the SNR is still above the capture ratio when the power Transmitter is operating. In this process, the power rf carrier is treated as an element of the noise and interference—in some installations it may be the largest single noise in the mix of naturally occurring background noise and interference.
  • [0060]
    The capture ratio depends on the precise type of rf modulation, the bandwidth of the rf signal and the bandwidth (or bit rate, if digital) of the baseband modulating input signal and the severity of fast fading due to movement of either or both of the transmitter or receiver in a multipath radio environment. For example, for the type of analog FM radio used historically with North American cellular (sometimes called AMPS), the capture ratio is approximately 63/1. This ratio is also frequently expressed as 18 dB, an equivalent expression. If the same input signal is used but the designed FM frequency deviation (and thus the rf bandwidth) decreases, the capture ratio increases, indicating that a higher SNR is required on each communication link for a low deviation FM signal. The underlying theory to explain this is well known
  • [0061]
    There are several methods used in the art to characterize the accuracy or fidelity of the reception of a radio signal. A widely accepted test is the SINAD test. A modified SINAD test, useful for testing and installing the present invention, is summarized in the following paragraphs as an example used to illustrate the kinds of techniques that can be used when minimization of the degradation of a nominally “same frequency” communications signal is an objective.
  • [0062]
    With the communications receiver operating with a known baseband test signal, the rf power signal can first be set at a frequency that is the nominal center frequency of the communication signal, a frequency corresponding to zero deviation (analog audio silence) for an analog FM signal. The maximum power level of the power carrier at the location of the communication receive antenna is determined by starting a transmit test at a low power level and then increase, at a controlled rate, the power-carrier power, until a pre-specified level of baseband “signal to noise” ratio occurs.
  • [0063]
    For example, a known baseband waveform is transmitted on the communication channel for test purposes, and a properly time-synchronized “clean” replica of that test waveform is adjusted to match the amplitude of the received baseband waveform, which is subtracted from the time-synchronized test waveform. This difference signal is defined as the baseband noise, n. The power content n is measured and compared to the baseband received signal output power s. The power carrier level is gradually increased. When the ratio of baseband signal to baseband noise exceeds the pre-specified SINAD value of, for example, 16/1 (also expressed as 12 dB) the corresponding rf interference level (which includes the power carrier) is at the maximum allowable level for that particular installation.
  • [0064]
    This embodiment of the measurement method deviates from traditional SINAD measurements. In traditional SINAD, the baseband signal is a sine wave audio frequency waveform, while in an embodiment, we can use any test waveform, including a digital waveform or square wave. Also, in the traditional SINAD test, the method of separating the “difference” signal (which comprises the effects of noise, interference and distortion) is to extract the audio sine wave by means of a standard narrow-band “notch” (single frequency reject) filter, which only works with an audio frequency baseband test sine wave. Again, our embodiments can use any baseband test waveform.
  • [0065]
    Incidentally, baseband power described above as s is the “sum” (combined effects) of the desired signal power, together with the undesired noise, interference and distortion; and n is the “sum” of noise, interference and distortion. The composite signal plus noise and interference is used in the numerator of these expressions simply because it is simpler to not attempt to remove the noise and interference from the s term; just a matter of convenience. Distortion could be represented by an additional term in the formula, but is usually discussed in the text but not symbolized in the formula in most literature in this subject area. These statements apply to both the traditional SINAD test and our modification as well.
  • [0066]
    As background information, we note that the results of our test will typically have a qualitative difference when comparing “capture ratio” types of modulation with AM family modulation. In the former case the “audio quality” of FM. For example, baseband (s/(n+i) “suddenly” becomes 1000 to one, or 30 dB) when the rf S/(N+I) exceeds the “capture ratio” appropriate for that signal. Baseband (s/(n+i) is only degraded when the rf S/(N+I) falls below the capture ratio.
  • [0067]
    In contrast, any of the AM family of signals, for example, broadcast AM, has no defined “capture ratio,” and the audio baseband (s/(n+i) value substantially “tracks” (is proportional to) the rf S/(N+I).
  • [0068]
    The use of 12 dB as a deciding value for baseband waveform in our test example is an existing industry standard for a traditional SINAD test for a baseband power analog FM mobile radio. Audio with a 12 dB signal to noise ratio sounds subjectively quite good for voice conversations, so the choice is not totally arbitrary. For digital communication channels, an appropriate maximum permissible bit error rate (BER), for example 2% erroneous bits with 98% accurate bits, can be used as a criterion, instead of baseband (s/(n+i), to determine when the interference from the power carrier is excessive. The maximum bit error rate must be commensurate with the amount and type of error protection code designed for and used on that digital channel. In the previous example, intrinsic error protection coding can function correctly in the face of a 2% bit error rate. To find the errors, our method of transmitting a known digital waveform may be used, but there are other methods of error bit counting as well. In some types of digital channels, for example digital cellular radio, error protection codes are already used as a part of the communication process protocol, and they can be used by our power transmission system to estimate the bit error rate on the communication channel. Such methods for estimating the bit error rate or word error rate by means of evaluating byproduct data arising from operation of error protection codes that are already an intrinsic part of the communications protocol of a channel are well known to those skilled in the art and are already used in digital cellular radio systems.
  • [0069]
    When an adequate communication receiver signal accuracy cannot be achieved simultaneously with delivery of rf power to the power Receiver while the power carrier frequency is set at the nominal center frequency of the communication channel, the more customary alternative of setting the power carrier frequency to the edge of the communication signal rf bandwidth (or even further from the center frequency) is still available to the installer.
  • [0070]
    Many modern communication and broadcast radio receivers already include a design feature called automatic gain control (AGC). AGC uses an automatic feedback control loop to dynamically adjust the gain (amplification) of typically the first (rf pre-amplifier) stages that amplify the receiver antenna signals. The purpose of this adjustment is to eventually have all signals from either high power vs. low power level transmitters, or nearby transmitters vs. distant transmitters (as measured at the Receiver antenna) arrive at the internal detector/discriminator all at a uniform amplitude or power level. This simplifies the design and improves the performance of the detector/discriminator and also means that when an excessive amount of power rf carrier occurs, as measured at the communications receiver antenna, that will cause the audio or baseband digital output signal to become smaller in amplitude (quieter in the case of analog FM or analog AM or SSB). SSB is described later.
  • [0071]
    Communication signals that are members of the so-called AM (amplitude modulation) “family” of modulation techniques use one or two “sidebands” (radio frequency “copies” of the analog input baseband waveform, with the frequency order inverted for one of the two sidebands only) together with a constant amplitude, constant frequency rf carrier sine wave arising at the Receiver in one of two design choices. In one design choice, the carrier frequency waveform is either transmitted from the communications Transmitter to the communications Receiver via the radio wave (called “carrier present”), along with the so-called “sideband(s).” In the second alternative design choice, the carrier is not sent via radio from the communications Transmitter but is generated locally at the communications Receiver and combined with the sidebands there (called “carrier absent”). Ordinary broadcast AM (in the frequency range 600 kHz to 1.6 MHz) is called DSB-AM (double sideband AM) since the broadcasting Transmitter sends the carrier and both sidebands. Analog television broadcasting of the picture (sound is sent via FM) occurs via a modified single side band (SSB) carrier present radio signal called vestigial SSB. Military and amateur radio operators use “pure” SSB; that is, one sideband present with the carrier absent. This last method uses a local oscillator in the communications receiver (called the beat frequency oscillator—BFO) to provide the necessary carrier at the demodulator. In some communication receivers, the BFO frequency (and amplitude) is adjusted manually.
  • [0072]
    In a carrier present system, if the frequency of the BFO oscillator is not close enough to the needed frequency, the audio output will contain an audio tone at the “difference” frequency fd=|fc−fb| (also called the beat frequency or audio heterodyne frequency), where fc is the carrier frequency and fb is the BFO frequency and the vertical bars surrounding the two frequency symbols represents the absolute value. In a carrier absent system, the two sidebands will be detected by a receiver with an erroneous value of fb but will appear at the output of the detector as a frequency shifted replica of the original sideband waveform. The amount of frequency shift will be fd in magnitude and the direction of frequency shift will be up or down according to whether fb is lower or higher than fc and also is opposite for each sideband. In short, if fd differs substantially from zero, the received communication output waveform will be significantly distorted.
  • [0073]
    In a practical system, the value of fd should be small enough so that the resulting detected communications waveform is close enough to its desired undistorted form so that the intended purpose of the radio communication can be achieved. In the case of ordinary speech, the detector output wavneeds not match the original input speech waveform so precisely, but the audio power spectrum of the output baseband signal must be sufficiently close to that of the original input voice signal. Experience has shown that an approximate value of fd<300 Hz is acceptable. For other applications, or carriage of other waveforms, such as for example a modem signal comprising an audio frequency FSK signal, a still smaller value of fd will typically be mandatory. In each such case one of ordinary skill can determine the correct value for fd by searching the scientific literature, by simple measurements, or via simple calculations. For example, if the audio frequency accuracy of the modem sine wave generator is ±15 Hz, and the bandwidth within which the detector filters can recognize an audio frequency corresponding to a binary 1 or 0 is ±25 Hz, then it is clear that the maximum value of fd is ±10 Hz.
  • [0074]
    To summarize, designers historically purposely avoid placing an interfering signal over a communication signal, but we do the opposite. The invention described in the present application does this when the “interfering” signal (our power carrier sinewave) is not modulated.
  • [0075]
    An embodiment makes use of a unique modification of the traditional SINAD test. Our modification versatile, and is adaptable to testing digital channels, while traditional SINAD is only usable for analog waveforms.
  • [0076]
    An embodiment uses a feedback control loop to control the frequency and/or amplitude of a potentially/possibly interfering zero-bandwidth (substantially un-modulated) radio source (that is, the power transmitter).
  • [0077]
    Any of the above techniques, even if disclosed for use with RF, can also be used with magnetic techniques, e.g., by using the RF produced according to these techniques to feed an electromagnetic field power coupling device.
  • [0078]
    The general structure and techniques, and more specific embodiments which can be used to effect different ways of carrying out the more general goals are described herein.
  • [0079]
    Although only a few embodiments have been disclosed in detail above, other embodiments are possible and the inventors intend these to be encompassed within this specification. The specification describes specific examples to accomplish a more general goal that may be accomplished in another way. This disclosure is intended to be exemplary, and the claims are intended to cover any modification or alternative which might be predictable to a person having ordinary skill in the art. For example, other antennas and movement or orientation methods can be used.
  • [0080]
    Also, the inventors intend that only those claims which use the words “means for . . . ” are intended to be interpreted under 35 USC 112, sixth paragraph. Moreover, no limitations from the specification are intended to be read into any claims, unless those limitations are expressly included in the claims. The operations described herein may be controlled by any kind of computer, either general purpose, or some specific purpose computer such as a workstation. The computer may also be a handheld computer, such as a PDA, cellphone, or laptop or a controller.
  • [0081]
    Where a specific numerical value is mentioned herein, it should be considered that the value may be increased or decreased by approximately 20%, while still staying within the teachings of the present application, unless some different range is specifically mentioned. Where a specified logical sense is used, the opposite logical sense is also intended to be encompassed.
Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3938018 *Sep 16, 1974Feb 10, 1976Dahl Ernest AInduction charging system
US4088999 *May 21, 1976May 9, 1978NasaRF beam center location method and apparatus for power transmission system
US4914539 *Mar 15, 1989Apr 3, 1990The Boeing CompanyRegulator for inductively coupled power distribution system
US5387818 *Nov 5, 1993Feb 7, 1995Leibowitz; Martin N.Downhill effect rotational apparatus and methods
US5396538 *Dec 24, 1991Mar 7, 1995Samsung Electronics Co., Ltd.Contactless digital power transmission and reception system in a radio telephone
US5397962 *Jun 29, 1992Mar 14, 1995Texas Instruments IncorporatedSource and method for generating high-density plasma with inductive power coupling
US5491715 *Jun 28, 1993Feb 13, 1996Texas Instruments Deutschland GmbhAutomatic antenna tuning method and circuit
US5519262 *Nov 17, 1992May 21, 1996Wood; Mark B.Near field power coupling system
US5596567 *Mar 31, 1995Jan 21, 1997Motorola, Inc.Wireless battery charging system
US5608417 *May 16, 1996Mar 4, 1997Palomar Technologies CorporationRF transponder system with parallel resonant interrogation series resonant response
US5621322 *Mar 9, 1995Apr 15, 1997Picker Nordstar Inc.VHF/RF volume antenna for magnetic resonance imaging including VHF applicator and RF coil arranged to provide perpendicular fields
US5734255 *Mar 13, 1996Mar 31, 1998Alaska Power Systems Inc.Control system and circuits for distributed electrical power generating stations
US5856710 *Aug 29, 1997Jan 5, 1999General Motors CorporationInductively coupled energy and communication apparatus
US6016046 *Jul 17, 1998Jan 18, 2000Sanyo Electric Co., Ltd.Battery pack
US6028413 *Sep 18, 1998Feb 22, 2000Perdix OyCharging device for batteries in a mobile electrical device
US6031708 *Dec 22, 1998Feb 29, 2000Schneider Electric SaInductive charge control device
US6040680 *Jul 20, 1998Mar 21, 2000Sanyo Electric Co., Ltd.Rechargeable battery pack and charging stand for charging the rechargeable battery pack by electromagnetic induction
US6040986 *Nov 27, 1998Mar 21, 2000Matsushita Electric Works, Ltd.Non-contact power transmitting device having simplified self-oscillation feedback loop which interrupts power transmission when no load is present
US6175124 *Jun 30, 1998Jan 16, 2001Lsi Logic CorporationMethod and apparatus for a wafer level system
US6184651 *Mar 20, 2000Feb 6, 2001Motorola, Inc.Contactless battery charger with wireless control link
US6337628 *Dec 29, 2000Jan 8, 2002Ntp, IncorporatedOmnidirectional and directional antenna assembly
US6341076 *Sep 30, 2000Jan 22, 2002Next Power CorporationLoss reduction circuit for switching power converters
US6507152 *Jul 12, 2001Jan 14, 2003Kansai Technology Licensing Organization Co., Ltd.Microwave/DC cyclotron wave converter having decreased magnetic field
US6523493 *Aug 1, 2000Feb 25, 2003Tokyo Electron LimitedRing-shaped high-density plasma source and method
US6556054 *Oct 2, 2000Apr 29, 2003Gas Research InstituteEfficient transmitters for phase modulated signals
US6879076 *Dec 9, 2003Apr 12, 2005Johnny D. LongEllipsoid generator
US6891287 *Jul 17, 2003May 10, 2005Les Produits Associes Lpa, S.A.Alternating current axially oscillating motor
US7012405 *Sep 12, 2002Mar 14, 2006Ricoh Company, Ltd.Charging circuit for secondary battery
US7164344 *Dec 24, 2003Jan 16, 2007Matsushita Electric Industrial Co., Ltd.Non-contact IC card reading/writing apparatus
US7167139 *Dec 27, 2004Jan 23, 2007Electronics And Telecommunications Research InstituteHexagonal array structure of dielectric rod to shape flat-topped element pattern
US7180265 *Oct 27, 2003Feb 20, 2007Nokia CorporationCharging device with an induction coil
US7180291 *Nov 25, 2003Feb 20, 2007Koninklijke Philips Electronics N.V.Degenerate birdcage coil and transmit/receive apparatus and method for same
US7209792 *Apr 26, 2002Apr 24, 2007Advanced Bionics CorporationRF-energy modulation system through dynamic coil detuning
US7212414 *Oct 20, 2003May 1, 2007Access Business Group International, LlcAdaptive inductive power supply
US7215061 *Nov 18, 2004May 8, 2007Seiko Epson CorporationMicromechanical electrostatic resonator
US7511500 *Feb 27, 2007Mar 31, 2009The Penn State Research FoundationDetecting quadrupole resonance signals using high temperature superconducting resonators
US7518267 *Oct 20, 2003Apr 14, 2009Access Business Group International LlcPower adapter for a remote device
US7525283 *Feb 28, 2005Apr 28, 2009Access Business Group International LlcContact-less power transfer
US7675197 *Jun 17, 2004Mar 9, 2010Auckland Uniservices LimitedApparatus and method for inductive power transfer
US7688036 *Jun 26, 2006Mar 30, 2010Battelle Energy Alliance, LlcSystem and method for storing energy
US7868482 *Oct 23, 2006Jan 11, 2011Powercast CorporationMethod and apparatus for high efficiency rectification for various loads
US20020017979 *Jan 10, 2001Feb 14, 2002Jens KrauseMethod of the transmission of data
US20020036977 *Aug 27, 2001Mar 28, 2002Koninklijke Philips Electronics N.V.Information carrier, apparatus, substrate, and system
US20020057161 *Jul 25, 2001May 16, 2002Matsushita Electric Works, Ltd.Non-contact electric power transmission apparatus
US20020057584 *Nov 13, 2001May 16, 2002Salcomp OyPower supply arrangement and inductively coupled battery charger with wirelessly coupled control, and method for wirelessly controlling a power supply arrangement and an inductively coupled battery charger
US20030090353 *Sep 30, 2002May 15, 2003Suzette RobinsonContactless transmission of power and information signals in a continuous rotation pan/tilt device
US20040001029 *Jun 27, 2002Jan 1, 2004Francis ParscheEfficient loop antenna of reduced diameter
US20040002835 *Jun 26, 2002Jan 1, 2004Nelson Matthew A.Wireless, battery-less, asset sensor and communication system: apparatus and method
US20050007239 *Apr 30, 2004Jan 13, 2005U.S.A. As Represented By The Administrator Of The National Aeronautics And Space AdministrationMagnetic field response measurement acquisition system
US20050017677 *Jul 24, 2003Jan 27, 2005Burton Andrew F.Method and system for providing induction charging having improved efficiency
US20050029351 *Jun 29, 2004Feb 10, 2005Matsushita Electric Industrial Co., Ltd.Noncontact IC card reader/writer
US20050043055 *Oct 14, 2003Feb 24, 2005Vance Scott L.Tunable parasitic resonators
US20050057422 *Aug 31, 2004Mar 17, 2005Matsushita Electric Industrial Co., Ltd.Gate antenna device
US20050075697 *Apr 30, 2004Apr 7, 2005Medtronic, Inc.External power source for an implantable medical device having an adjustable carrier frequency and system and method related therefore
US20050104457 *Mar 6, 2003May 19, 2005Alain JordanImplantable device
US20060017438 *Jul 26, 2004Jan 26, 2006Mullen Charles GMultiple tuned scroll coil
US20060061325 *Sep 21, 2004Mar 23, 2006Qingfeng TangApparatus for inductively recharging batteries
US20060071790 *Sep 29, 2004Apr 6, 2006Duron Mark WReverse infrastructure location system and method
US20060094449 *Dec 16, 2004May 4, 2006Interdigital Technology CorporationMethod and apparatus for preventing communication link degradation due to the disengagement or movement of a self-positioning transceiver
US20060103355 *Nov 16, 2004May 18, 2006Joseph PatinoMethod and system for selectively charging a battery
US20070010295 *Jul 6, 2006Jan 11, 2007Firefly Power Technologies, Inc.Power transmission system, apparatus and method with communication
US20070029965 *Sep 23, 2005Feb 8, 2007City University Of Hong KongRechargeable battery circuit and structure for compatibility with a planar inductive charging platform
US20070046433 *Aug 28, 2006Mar 1, 2007Somnath MukherjeeSystem for identifying radio-frequency identification devices
US20070054705 *Sep 6, 2005Mar 8, 2007Creative Technology Ltd.Wireless apparatus with multiple power and input sources
US20070060221 *Sep 12, 2005Mar 15, 2007Motorola, Inc.Speaker voice coil antenna
US20070082611 *Oct 6, 2006Apr 12, 2007Terranova Domenic FWireless communication over a transducer device
US20070091006 *Feb 16, 2006Apr 26, 2007Sanmina-Sci, A Delaware CorporationSelf-tuning radio frequency identification antenna system
US20070096910 *Jul 14, 2006May 3, 2007Hewlett-Packard Development Company, L.P.Inductively powered transponder device
US20070103110 *Oct 24, 2006May 10, 2007Samsung Electronics Co., Ltd.Apparatus and method of wirelessly sharing power by inductive method
US20070103291 *Oct 24, 2006May 10, 2007Hewlett-Packard Development CompanyInductively powered devices
US20070105524 *Nov 7, 2005May 10, 2007Fullam Scott FRemotely powered wireless microphone
US20070114945 *Nov 21, 2005May 24, 2007Mattaboni Paul JInductively-coupled RF power source
US20070120678 *Nov 30, 2005May 31, 2007Joshua PosamentierRFID enabled multiband antenna
US20080003963 *Jun 30, 2006Jan 3, 2008Microsoft CorporationSelf-powered radio integrated circuit with embedded antenna
US20080014897 *Jan 17, 2007Jan 17, 2008Cook Nigel PMethod and apparatus for delivering energy to an electrical or electronic device via a wireless link
US20080054638 *Aug 30, 2007Mar 6, 2008Powercast CorporationHybrid power harvesting and method
US20080067874 *Sep 14, 2007Mar 20, 2008Ryan TsengMethod and apparatus for wireless power transmission
US20080093934 *Sep 7, 2005Apr 24, 2008Semiconductor Energy Laboratory Co., Ltd.Wireless Chip
US20080108862 *Dec 31, 2007May 8, 2008Allergan Medical S.A.Implantable device
US20080122294 *Nov 23, 2004May 29, 2008Sew-Eurodrive Gmbh & Co. KgSystem
US20090002175 *Oct 26, 2005Jan 1, 2009Hewlett-Packard Development Company, L.P.Power Transfer for Transponder Devices
US20090009177 *Jul 2, 2007Jan 8, 2009Nesscap Co., Ltd.Voltage monitoring method and circuit for electrical energy storage device
US20090026907 *Aug 14, 2006Jan 29, 2009Coldtrack, LlcHierarchical Sample Storage System
US20090045772 *Jun 10, 2008Feb 19, 2009Nigelpower, LlcWireless Power System and Proximity Effects
US20090051224 *Aug 11, 2008Feb 26, 2009Nigelpower, LlcIncreasing the q factor of a resonator
US20090052721 *Dec 14, 2006Feb 26, 2009Koninklijke Philips Electronics, N.V.Combined inductive charging coil and audio speaker for use in a personal care appliance
US20090058361 *Jun 2, 2008Mar 5, 2009Michael Sasha JohnSystems and Methods for Wireless Power
US20090072627 *Sep 14, 2008Mar 19, 2009Nigelpower, LlcMaximizing Power Yield from Wireless Power Magnetic Resonators
US20090079268 *Sep 16, 2008Mar 26, 2009Nigel Power, LlcTransmitters and receivers for wireless energy transfer
US20090102296 *Dec 28, 2007Apr 23, 2009Powercast CorporationPowering cell phones and similar devices using RF energy harvesting
US20090102419 *May 4, 2006Apr 23, 2009Gwang-Hee GwonWireless charger decreased in variation of charging efficiency
US20090109102 *Jan 8, 2009Apr 30, 2009Murata Manufacturing Co., Ltd.Antenna and radio ic device
US20090111531 *Oct 24, 2007Apr 30, 2009Nokia CorporationMethod and apparatus for transferring electrical power in an electronic device
US20100013434 *Jun 8, 2007Jan 21, 2010Elektromotive Ltd.Charging station
US20100068998 *Jan 30, 2008Mar 18, 2010Emmanuel ZyamboWireless interface
US20110031821 *Oct 11, 2010Feb 10, 2011Powercast CorporationMethod and Apparatus for Implementation of a Wireless Power Supply
US20110050166 *Nov 9, 2010Mar 3, 2011Qualcomm IncorporatedMethod and system for powering an electronic device via a wireless link
US20110069516 *Nov 22, 2010Mar 24, 2011Powercast CorporationMethod and apparatus for high efficiency rectification for various loads
US20110074349 *May 28, 2009Mar 31, 2011Georgia Tech Research CorporationSystems and methods for providing wireless power to a portable unit
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7741734Jun 22, 2010Massachusetts Institute Of TechnologyWireless non-radiative energy transfer
US7825543Mar 26, 2008Nov 2, 2010Massachusetts Institute Of TechnologyWireless energy transfer
US8022576Sep 20, 2011Massachusetts Institute Of TechnologyWireless non-radiative energy transfer
US8035255Nov 6, 2009Oct 11, 2011Witricity CorporationWireless energy transfer using planar capacitively loaded conducting loop resonators
US8076800Mar 31, 2009Dec 13, 2011Massachusetts Institute Of TechnologyWireless non-radiative energy transfer
US8076801May 14, 2009Dec 13, 2011Massachusetts Institute Of TechnologyWireless energy transfer, including interference enhancement
US8084889Dec 27, 2011Massachusetts Institute Of TechnologyWireless non-radiative energy transfer
US8097983May 8, 2009Jan 17, 2012Massachusetts Institute Of TechnologyWireless energy transfer
US8106539Mar 11, 2010Jan 31, 2012Witricity CorporationWireless energy transfer for refrigerator application
US8304935Dec 28, 2009Nov 6, 2012Witricity CorporationWireless energy transfer using field shaping to reduce loss
US8324759Dec 28, 2009Dec 4, 2012Witricity CorporationWireless energy transfer using magnetic materials to shape field and reduce loss
US8344552Jan 1, 2013Qualcomm IncorporatedAntennas and their coupling characteristics for wireless power transfer via magnetic coupling
US8362651Oct 1, 2009Jan 29, 2013Massachusetts Institute Of TechnologyEfficient near-field wireless energy transfer using adiabatic system variations
US8373514Oct 13, 2008Feb 12, 2013Qualcomm IncorporatedWireless power transfer using magneto mechanical systems
US8378522Sep 14, 2008Feb 19, 2013Qualcomm, IncorporatedMaximizing power yield from wireless power magnetic resonators
US8378523Feb 19, 2013Qualcomm IncorporatedTransmitters and receivers for wireless energy transfer
US8395282Mar 31, 2009Mar 12, 2013Massachusetts Institute Of TechnologyWireless non-radiative energy transfer
US8395283Dec 16, 2009Mar 12, 2013Massachusetts Institute Of TechnologyWireless energy transfer over a distance at high efficiency
US8400017Mar 19, 2013Witricity CorporationWireless energy transfer for computer peripheral applications
US8400018Dec 16, 2009Mar 19, 2013Massachusetts Institute Of TechnologyWireless energy transfer with high-Q at high efficiency
US8400019Dec 16, 2009Mar 19, 2013Massachusetts Institute Of TechnologyWireless energy transfer with high-Q from more than one source
US8400020Mar 19, 2013Massachusetts Institute Of TechnologyWireless energy transfer with high-Q devices at variable distances
US8400021Dec 16, 2009Mar 19, 2013Massachusetts Institute Of TechnologyWireless energy transfer with high-Q sub-wavelength resonators
US8400022Dec 23, 2009Mar 19, 2013Massachusetts Institute Of TechnologyWireless energy transfer with high-Q similar resonant frequency resonators
US8400023Dec 23, 2009Mar 19, 2013Massachusetts Institute Of TechnologyWireless energy transfer with high-Q capacitively loaded conducting loops
US8400024Dec 30, 2009Mar 19, 2013Massachusetts Institute Of TechnologyWireless energy transfer across variable distances
US8410636Apr 2, 2013Witricity CorporationLow AC resistance conductor designs
US8441154Oct 28, 2011May 14, 2013Witricity CorporationMulti-resonator wireless energy transfer for exterior lighting
US8447234Apr 21, 2006May 21, 2013Qualcomm IncorporatedMethod and system for powering an electronic device via a wireless link
US8461719Sep 25, 2009Jun 11, 2013Witricity CorporationWireless energy transfer systems
US8461720Dec 28, 2009Jun 11, 2013Witricity CorporationWireless energy transfer using conducting surfaces to shape fields and reduce loss
US8461721Jun 11, 2013Witricity CorporationWireless energy transfer using object positioning for low loss
US8461722Dec 29, 2009Jun 11, 2013Witricity CorporationWireless energy transfer using conducting surfaces to shape field and improve K
US8466583Nov 7, 2011Jun 18, 2013Witricity CorporationTunable wireless energy transfer for outdoor lighting applications
US8471410Dec 30, 2009Jun 25, 2013Witricity CorporationWireless energy transfer over distance using field shaping to improve the coupling factor
US8476788Dec 29, 2009Jul 2, 2013Witricity CorporationWireless energy transfer with high-Q resonators using field shaping to improve K
US8482157Aug 11, 2008Jul 9, 2013Qualcomm IncorporatedIncreasing the Q factor of a resonator
US8482158Dec 28, 2009Jul 9, 2013Witricity CorporationWireless energy transfer using variable size resonators and system monitoring
US8487480Dec 16, 2009Jul 16, 2013Witricity CorporationWireless energy transfer resonator kit
US8497601Apr 26, 2010Jul 30, 2013Witricity CorporationWireless energy transfer converters
US8552592Feb 2, 2010Oct 8, 2013Witricity CorporationWireless energy transfer with feedback control for lighting applications
US8569914Dec 29, 2009Oct 29, 2013Witricity CorporationWireless energy transfer using object positioning for improved k
US8576743 *Dec 21, 2011Nov 5, 2013Qualcomm IncorporatedApparatus and methods for estimating an unknown frequency error of a tone signal
US8587153Dec 14, 2009Nov 19, 2013Witricity CorporationWireless energy transfer using high Q resonators for lighting applications
US8587155Mar 10, 2010Nov 19, 2013Witricity CorporationWireless energy transfer using repeater resonators
US8598743May 28, 2010Dec 3, 2013Witricity CorporationResonator arrays for wireless energy transfer
US8598747Nov 18, 2011Dec 3, 2013Apple Inc.Wireless power utilization in a local computing environment
US8618696Feb 21, 2013Dec 31, 2013Witricity CorporationWireless energy transfer systems
US8629576Mar 28, 2008Jan 14, 2014Qualcomm IncorporatedTuning and gain control in electro-magnetic power systems
US8629578Feb 21, 2013Jan 14, 2014Witricity CorporationWireless energy transfer systems
US8643326Jan 6, 2011Feb 4, 2014Witricity CorporationTunable wireless energy transfer systems
US8667452Nov 5, 2012Mar 4, 2014Witricity CorporationWireless energy transfer modeling tool
US8669676Dec 30, 2009Mar 11, 2014Witricity CorporationWireless energy transfer across variable distances using field shaping with magnetic materials to improve the coupling factor
US8686598Dec 31, 2009Apr 1, 2014Witricity CorporationWireless energy transfer for supplying power and heat to a device
US8692410Dec 31, 2009Apr 8, 2014Witricity CorporationWireless energy transfer with frequency hopping
US8692412Mar 30, 2010Apr 8, 2014Witricity CorporationTemperature compensation in a wireless transfer system
US8710701Dec 17, 2012Apr 29, 2014Qualcomm IncorporatedAntennas and their coupling characteristics for wireless power transfer via magnetic coupling
US8716903Mar 29, 2013May 6, 2014Witricity CorporationLow AC resistance conductor designs
US8723366Mar 10, 2010May 13, 2014Witricity CorporationWireless energy transfer resonator enclosures
US8729737Feb 8, 2012May 20, 2014Witricity CorporationWireless energy transfer using repeater resonators
US8731116Feb 6, 2012May 20, 2014Access Business Group International LlcSystem and method of providing communications in a wireless power transfer system
US8744390 *Mar 29, 2012Jun 3, 2014Adc Telecommunications, Inc.Systems and methods for adjusting system tests based on detected interference
US8760007Dec 16, 2009Jun 24, 2014Massachusetts Institute Of TechnologyWireless energy transfer with high-Q to more than one device
US8760008Dec 30, 2009Jun 24, 2014Massachusetts Institute Of TechnologyWireless energy transfer over variable distances between resonators of substantially similar resonant frequencies
US8766485Dec 30, 2009Jul 1, 2014Massachusetts Institute Of TechnologyWireless energy transfer over distances to a moving device
US8772971Dec 30, 2009Jul 8, 2014Massachusetts Institute Of TechnologyWireless energy transfer across variable distances with high-Q capacitively-loaded conducting-wire loops
US8772972Dec 30, 2009Jul 8, 2014Massachusetts Institute Of TechnologyWireless energy transfer across a distance to a moving device
US8772973Aug 20, 2010Jul 8, 2014Witricity CorporationIntegrated resonator-shield structures
US8791599Dec 30, 2009Jul 29, 2014Massachusetts Institute Of TechnologyWireless energy transfer to a moving device between high-Q resonators
US8796885Apr 20, 2012Aug 5, 2014Apple Inc.Combining power from multiple resonance magnetic receivers in resonance magnetic power system
US8796886Apr 20, 2012Aug 5, 2014Apple Inc.Automatically tuning a transmitter to a resonance frequency of a receiver
US8805530Jun 2, 2008Aug 12, 2014Witricity CorporationPower generation for implantable devices
US8829734 *Jan 6, 2014Sep 9, 2014Glenn GulakMethod and system for maximum achievable efficiency in near-field coupled wireless power transfer systems
US8836172Nov 15, 2012Sep 16, 2014Massachusetts Institute Of TechnologyEfficient near-field wireless energy transfer using adiabatic system variations
US8847548Aug 7, 2013Sep 30, 2014Witricity CorporationWireless energy transfer for implantable devices
US8875086Dec 31, 2013Oct 28, 2014Witricity CorporationWireless energy transfer modeling tool
US8884581May 18, 2011Nov 11, 2014Qualcomm IncorporatedAdaptive wireless energy transfer system
US8901778 *Oct 21, 2011Dec 2, 2014Witricity CorporationWireless energy transfer with variable size resonators for implanted medical devices
US8901779Oct 21, 2011Dec 2, 2014Witricity CorporationWireless energy transfer with resonator arrays for medical applications
US8907531Oct 21, 2011Dec 9, 2014Witricity CorporationWireless energy transfer with variable size resonators for medical applications
US8912687Nov 3, 2011Dec 16, 2014Witricity CorporationSecure wireless energy transfer for vehicle applications
US8922066Oct 17, 2011Dec 30, 2014Witricity CorporationWireless energy transfer with multi resonator arrays for vehicle applications
US8928276Mar 23, 2012Jan 6, 2015Witricity CorporationIntegrated repeaters for cell phone applications
US8933594Oct 18, 2011Jan 13, 2015Witricity CorporationWireless energy transfer for vehicles
US8937408Apr 20, 2011Jan 20, 2015Witricity CorporationWireless energy transfer for medical applications
US8946938Oct 18, 2011Feb 3, 2015Witricity CorporationSafety systems for wireless energy transfer in vehicle applications
US8947186Feb 7, 2011Feb 3, 2015Witricity CorporationWireless energy transfer resonator thermal management
US8957549Nov 3, 2011Feb 17, 2015Witricity CorporationTunable wireless energy transfer for in-vehicle applications
US8963488Oct 6, 2011Feb 24, 2015Witricity CorporationPosition insensitive wireless charging
US9035499Oct 19, 2011May 19, 2015Witricity CorporationWireless energy transfer for photovoltaic panels
US9059598Oct 21, 2011Jun 16, 2015Samsung Electronics Co., LtdWireless charging method and apparatus
US9065286Jun 12, 2014Jun 23, 2015Massachusetts Institute Of TechnologyWireless non-radiative energy transfer
US9065423Sep 14, 2011Jun 23, 2015Witricity CorporationWireless energy distribution system
US9070505 *Aug 19, 2011Jun 30, 2015Tdk CorporationCoil apparatus and non-contact power transmission apparatus
US9086864Nov 10, 2010Jul 21, 2015Apple Inc.Wireless power utilization in a local computing environment
US9093853Jan 30, 2012Jul 28, 2015Witricity CorporationFlexible resonator attachment
US9095729Jan 20, 2012Aug 4, 2015Witricity CorporationWireless power harvesting and transmission with heterogeneous signals
US9101777Aug 29, 2011Aug 11, 2015Witricity CorporationWireless power harvesting and transmission with heterogeneous signals
US9105959Sep 4, 2012Aug 11, 2015Witricity CorporationResonator enclosure
US9106203Nov 7, 2011Aug 11, 2015Witricity CorporationSecure wireless energy transfer in medical applications
US9106269Dec 6, 2011Aug 11, 2015Access Business Group International LlcSystem and method for providing communications in a wireless power supply
US9124120Jun 10, 2008Sep 1, 2015Qualcomm IncorporatedWireless power system and proximity effects
US9130602Jan 17, 2007Sep 8, 2015Qualcomm IncorporatedMethod and apparatus for delivering energy to an electrical or electronic device via a wireless link
US9154002Jan 24, 2011Oct 6, 2015Access Business Group International LlcSystems and methods for detecting data communication over a wireless power link
US9160203Oct 6, 2011Oct 13, 2015Witricity CorporationWireless powered television
US9166413 *Jan 7, 2011Oct 20, 2015Sony CorporationWireless power supplying system
US9184595Feb 13, 2010Nov 10, 2015Witricity CorporationWireless energy transfer in lossy environments
US9246336Jun 22, 2012Jan 26, 2016Witricity CorporationResonator optimizations for wireless energy transfer
US9287607Jul 31, 2012Mar 15, 2016Witricity CorporationResonator fine tuning
US9306635Jan 28, 2013Apr 5, 2016Witricity CorporationWireless energy transfer with reduced fields
US9318257Oct 18, 2012Apr 19, 2016Witricity CorporationWireless energy transfer for packaging
US9318898Jun 25, 2015Apr 19, 2016Witricity CorporationWireless power harvesting and transmission with heterogeneous signals
US9318922Mar 15, 2013Apr 19, 2016Witricity CorporationMechanically removable wireless power vehicle seat assembly
US9343922Jun 27, 2012May 17, 2016Witricity CorporationWireless energy transfer for rechargeable batteries
US9344155Jan 7, 2013May 17, 2016Access Business Group International LlcInterference mitigation for multiple inductive systems
US9354620 *Nov 3, 2014May 31, 2016Powermat Technologies Ltd.System and method for triggering power transfer across an inductive power coupling and non resonant transmission
US9369182Jun 21, 2013Jun 14, 2016Witricity CorporationWireless energy transfer using variable size resonators and system monitoring
US9384885Aug 6, 2012Jul 5, 2016Witricity CorporationTunable wireless power architectures
US9396867Apr 14, 2014Jul 19, 2016Witricity CorporationIntegrated resonator-shield structures
US9404954Oct 21, 2013Aug 2, 2016Witricity CorporationForeign object detection in wireless energy transfer systems
US9407332Apr 4, 2014Aug 2, 2016Access Business Group International LlcSystem and method of providing communications in a wireless power transfer system
US9421388Aug 7, 2014Aug 23, 2016Witricity CorporationPower generation for implantable devices
US9442172Sep 10, 2012Sep 13, 2016Witricity CorporationForeign object detection in wireless energy transfer systems
US9444265May 22, 2012Sep 13, 2016Massachusetts Institute Of TechnologyWireless energy transfer
US9444517 *Dec 1, 2011Sep 13, 2016Triune Systems, LLCCoupled inductor power transfer system
US9444520Jul 19, 2013Sep 13, 2016Witricity CorporationWireless energy transfer converters
US20070222542 *Jul 5, 2006Sep 27, 2007Joannopoulos John DWireless non-radiative energy transfer
US20090072627 *Sep 14, 2008Mar 19, 2009Nigelpower, LlcMaximizing Power Yield from Wireless Power Magnetic Resonators
US20090195333 *Mar 31, 2009Aug 6, 2009John D JoannopoulosWireless non-radiative energy transfer
US20090213028 *Feb 26, 2009Aug 27, 2009Nigel Power, LlcAntennas and Their Coupling Characteristics for Wireless Power Transfer via Magnetic Coupling
US20090267709 *Oct 29, 2009Joannopoulos John DWireless non-radiative energy transfer
US20100045114 *Feb 25, 2010Sample Alanson PAdaptive wireless power transfer apparatus and method thereof
US20100081379 *Sep 25, 2009Apr 1, 2010Intel CorporationWirelessly powered speaker
US20110025132 *Oct 7, 2010Feb 3, 2011Olympus CorporationPower transmission system
US20110043049 *Dec 29, 2009Feb 24, 2011Aristeidis KaralisWireless energy transfer with high-q resonators using field shaping to improve k
US20110050166 *Nov 9, 2010Mar 3, 2011Qualcomm IncorporatedMethod and system for powering an electronic device via a wireless link
US20110130093 *Jun 3, 2010Jun 2, 2011Broadcom CorporationWireless power and wireless communication integrated circuit
US20110175455 *Jul 21, 2011Sony CorporationWireless power supplying system
US20110181123 *Oct 9, 2008Jul 28, 2011Toyota Jidosha Kabushiki KaishaNon-contact power reception device and vehicle including the same
US20110204711 *Aug 25, 2011Access Business Group International LlcSystems and methods for detecting data communication over a wireless power link
US20120040613 *May 7, 2010Feb 16, 2012Canon Kabushiki KaishaPower-supplying device, control method of the same, and power supply system
US20120043826 *Aug 19, 2011Feb 23, 2012Tdk CorporationCoil apparatus and non-contact power transmission apparatus
US20120139357 *Jun 7, 2012Triune Ip LlcCoupled Inductor Power Transfer System
US20120164943 *Jun 28, 2012Broadcom CorporationIntegrated wireless resonant power charging and communication channel
US20120235633 *Oct 21, 2011Sep 20, 2012Kesler Morris PWireless energy transfer with variable size resonators for implanted medical devices
US20120327793 *Dec 21, 2011Dec 27, 2012Qualcomm IncorporatedApparatus and methods for estimating an unknown frequency error of a tone signal
US20130069440 *Mar 21, 2013Kabushiki Kaisha ToshibaIncoming circuit using magnetic resonant coupling
US20130257172 *Mar 28, 2013Oct 3, 2013Ross E. TeggatzRemote energy transfer system
US20130260705 *Mar 29, 2012Oct 3, 2013Lgc Wireless, LlcSystems and methods for adjusting system tests based on detected interference
US20150054355 *Nov 3, 2014Feb 26, 2015Powermat Technologies Ltd.System and method for triggering power transfer across an inductive power coupling and non resonant transmission
CN102130511A *Jan 6, 2011Jul 20, 2011索尼公司Wireless power supplying system
CN102570629A *Nov 23, 2011Jul 11, 2012苹果公司Wireless power utilization in a local computing environment
CN102906655A *Jan 14, 2011Jan 30, 2013海尔集团公司Support frame adjustment device for wireless power transmission apparatus
EP2346136A1 *Jan 13, 2010Jul 20, 2011Universität Duisburg-EssenApparatus for generating an alternating magnetic field and apparatus for providing an effective power from an alternating magnetic field
EP2630718A2 *Oct 21, 2011Aug 28, 2013Samsung Electronics Co., LtdWireless charging method and apparatus
EP2800241A4 *Dec 27, 2011Jul 1, 2015Chugoku Electric PowerContactless power supply system, power supply device, and method for controlling contactless power supply system
EP2991185A3 *Sep 30, 2011Jun 22, 2016Intel CorporationWireless power transfer apparatus and method thereof
WO2011032786A1 *Aug 10, 2010Mar 24, 2011Dsm Ip Assets B.V.Removal of urea and ammonia from exhaust gases
WO2011146661A3 *May 18, 2011Nov 8, 2012Qualcomm IncorporatedAdaptive wireless energy transfer system
WO2012071268A2 *Nov 18, 2011May 31, 2012Apple Inc.Wireless power utilization in a local computing environment
WO2012071268A3 *Nov 18, 2011Apr 25, 2013Apple Inc.Wireless power utilization in a local computing environment
WO2012094822A1 *Jan 14, 2011Jul 19, 2012Haier Group CorporationSupport frame adjustment device for wireless power transmission apparatus
WO2014111817A2 *Jan 6, 2014Jul 24, 2014Glenn GulakMethod and system for maximum achievable efficiency in near-field coupled wireless power transfer systems
WO2014111817A3 *Jan 6, 2014Dec 4, 2014Glenn GulakMethod and system for maximum achievable efficiency in near-field coupled wireless power transfer systems
Classifications
U.S. Classification307/104
International ClassificationH02J17/00
Cooperative ClassificationH02J5/005
European ClassificationH02J5/00T
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Jun 18, 2008ASAssignment
Owner name: NIGEL POWER LLC, CALIFORNIA
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Owner name: QUALCOMM INCORPORATED, CALIFORNIA
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